Rotary pump or the like



Oct. 7, 1947. N. DOUGLAS 2,428,619

ROTARY PUMP OR THE LIKE Filed Nov. 6, 1944 6 Sheets-Sheet 1 Num.

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Oct. 7, 1947. N, DOUGLAS Y 2,428,619

ROTARY PUM1 3 OR THE LIKE mi( IIHI l Q @n 3 I INVENTOR:

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ATTORNEYS.

Oct. 7, 1947. N.` DOUGLAS l vROTARY PUMP OR THE LIKE 6 sheets-sheet sFiled Nov. 6, 1944 Oct. 7, 1947- N. DOUGLAS ROTARY PUMP OR THE LIKEFiled Nov. e, 1944 e sheets-shea 4 Oct. 7, 1947. N. DOUGLAS 2,423,619

ROTARY PUMP OR THE LIKE Filed Nov. 6, 1944 6 Sheets-Sheet 5 Jay Z, 74172 /67 Clttorneg! 7 N. DOUGLAS k ROTARY PUMP 0R THE LIKE" ssheets-sheet e Filed Nov. e. 1944 IN VEN TOR. /Ya/'e/aqy.:

BY @W7/MJ Patented Oct. 7, 1947 UNITED STATES Plrr:NTl orner:

Norvel Douglas, Dallas, Tex.

Application November 6, 1944, Serial No'. 562,072-

' which is expandedl and contracted progressively along the lengththereof by a rotatable eccentric and Which requires no valves, packing,or similar mechanisms to control flow and prevent leakage of fluid.

Other objects of the invention are to provide a pump structureespecially adapted to build up relatively high pressures on fluidscontaining abrasives and similar substances that in ordinaryY pumps asheretofore constructed are destructive to the packings, valves, andsliding surfaces; to

at relatively low speeds; to provide'a pump construction for maintaininga substantially constructure .having long life and trouble-freevoperation even' when handling abrasive' fluids.

It is also an object to provide a pump structure which is adapted forconstruction from materials selected so that they are suited to thecharacter of the fluid being operated on by the pump.

In accomplishing these and other objects of the invention, I haveprovided improved structure, the preferred form of which is illustratedin the accompanying drawings wherein:

Fig. l is a longitudinal section through a pump embodying the featuresof the present invention.

Fig, 2 is a lcross section through the pump on the line 2--2 of Fig. l.V

Fig. 3 is a similar section on the line 3-3 of Fig. 1.

Fig. 4 is a perspective view of the subbase of the pump which cooperateswith abase'manifold for anchoring the fluid intake and displacementchambers of the pump. l i

Fig. 5 is a perspective View of the base manifold of the pump.

l Fig. 6 is a perspective View partly in section of one of the fluidintake and displacement chambers.

Fig. 7 is a cross sectionthrough the base manifold particularlyillustrating the fluid inlet and outlet connections of the pump.

Fig. 8 is a fragmentary section of a liquidcooled gas compressorembodying the features of the present invention.

Fig. 9 is a longitudinal Vertical section through a modified form of theinvention wherein the pumping chamber is formed onlone side by a rigidstator and on the other by yan elastic member.

9 Claims. (Cl. 103-149) provide a pump structure having ylarge capacityAtinuous uniform pressure; and to provide a pump Fig. 10 is acrosssection through the pump on the line IU-IU of Fig. 9. 4

Fig. 11 is a cross section on the line II-II of Fig. 9.

Fig. 12 is a perspective view partly in section of one ofthe pistonunits of' the pump illustrated in Fig. 9.

Fig. 13 isv a perspective view partly broken away of one of the statorunits.

Fig. 14 is an enlarged fragmentary section through the elastic member,particularly illustrating arrangement of the reinforcing cords.

Fig. 15 is a perspective View of oneof the piston guides.

Referring more in detail to the drawings:

The pump illustrated includes, a horizontally disposed, substantiallycylindrical case l containing one o r more operating units, here shownas twoinnu'mber-and generally designated 2 and 3 andarranged` to operate180i out of phase whereby substantially continuous uniform pressure vismaintained on the discharge side of the pump.

The case I includes a substantially cylindrical wall 4 closed at one endby a Wall 5 and at the opposite end by a removable plate 6. The lowerportion of the case has a depending offset I pro vided with alongitudinal opening 8 terminating short of the ends ofthe case andprovided along the sidesthereof with inset shoulders 9 and l0 to seat asubbase member II. The end Wall 5 is preferably formed integrally withthe .cylindrical Wall of the case andI has an axial bearing housing I2facing inwardly of the case to mount the outer race I3 of ananti-friction bearing I4. The removableend plate 6 has a similar axiallypositioned bearing housing I5 facing inwardly to mount the outer race I6of ananti-friction bearing I1, which bearings have inner races I8 andIBfmountingthe journals 20 and 2.I of 'a shaft 22 as later described.The'end plate S'has arcuately spaced openings 23 in the peripherythrough which fastening devices such as studs 24 are projected intothreaded sockets 25 formed in the wall 4 at the open end thereof as bestshown in Fig.v

1, the studs being provided with nuts26 bywhich the end plate isretained in vsealing contact with a gasket 2l to retain lubricant withinthe case as later described. The axial portion of the plate' 6 has anopening-28 therein through which a reduced end 29 of the eccentric shaftis projected.

for mounting a suitable driving element such as I a gear, pulley, orthelike, to .couple the pump with -a prime mover (notshown). The opening28 is encircled by an annular recess 30 for mounting a 4packing'element3l lto seal about the end of the shaft and prevent escape of lubricanttherethrough. The subbase includes a plate portion 32 having marginalsides 33 and 34 and ends 35` and 36 seated against a gasket 31 bearingupon the shoulders 9 and which is retained in sealing contact byfastening devices 38 that are projected' through openings 39 in theplate and into threaded sockets (not shown) in the offset portioni ofthecase for closing the opening thereinto. The subbase has pairs ofport-like openings 40-4I and l2-43. The port-like openings are formed inbosses 44 and 45 projecting up-l wardly into the opening 8 of the case`*and the por-tsv of each pair are located on opposite sides of alongitudinally extending rib 46 for a purpose later described. Each portis of elongated form and has upwardly and inwardly converging side faces41 and 48 terminating in collar-like faces 49`adapted to embrace theterminal ends of the elastic intake and displacement chambers 50 and 5|as later described. The lower face of the plate surrounding each of theports has shoulder-like recesses 52 for accommodating flanged ends for apurpose later described.

The case I seats upon a base manifold 53 which includes an elongatedhollow body having side walls 54--55, end walls 56-51, and top andbottom walls 58-59. The top wall 58 is provided with elongated pairs oflports 606| and 62-63 registering with the ports in the subbase andencompassed by upwardly extending flanges 64 having upwardly andinwardly converging outer faces 05 conforming to the taper of the faces4 1 of -the subbasebut which are spaced therefrom supply (not shown) anda fluid receiver (also not shown) .l The base manifold is secured to thebottom of the case by fastening devices such as studs 12 that areprojected through ap'ertured ears k13 extending 4laterally from the basemanifold and into threaded sockets 14 formed in the depending extensionof the base, the studs being y insert opening II I closed by a plug H2.

provided with nuts 15 by which thebase maniv fold is drawn into contactwith the casing and for anchoring the previously mentioned elasticchambers. The base manifold also includes feet 16 projecting from therespective corners thereof for supporting the pump, the feet beingprovided with suitable openings through which fastening devices (notshown) may be inserted to anchor the pump to a, suitable support.

The units 2 and 3 each includes an elastic tube having relatively flatparallel inner and outer walls 11 and 18 connected at the ends thereofas at 10 and 80 to form substantially horseshoe-shaped chambers 8| and82. The legs 83 of the chambers terminate in collars 84 having flanges85 adapted to seat within the shoulders 52 when the collars are clampedbetween the plastic material such as rubber, synthetic rub-` ber, or thelike suitable for the fluid operated upon by the pump. The outer wall 18of each elastic chamber, is vulcanized or suitably ce- 'by the liner.

the shaft 22.

mented to a sleeve-like linerl 81, which liner is snugly sleeved withinthe case and anchored in position by fastening devices such as capscrews 88 projected through openings 89 in the wall 4 of the case andinto threaded sockets 90 carried The inner walls 18 of the elasticchambers are similarly fixed to sleeve-like liners 9| that are similarlyattached yto the peripherial faces of eccentrically supported cylindersdesignated 92 for the unit 2,.and 93 for the unit 3..

The cylinders have longitudinal grooves 94 on the undersides thereofwhich receive therein the rib 46 on the subbase which -positions thecylinders and prevents rotation thereof upon operation of eccentrics 95and 96 that are formed on The eccentrics 95 and 96 each include a pairof circumferential raised portions 91 and 98 on the shaft for seatingthe inner and outer races |03 and |04 seated within internal shoulders|05 and |06 formed within the eccentrically-supported cylinders as best.shown in Fig. 1. The outer races of the anti-friction bearings areretained from inward movement with respect to the eccentric cylinder lbyribs |01 and .the inner races are retained from outward movement on theeccentric portions of the shaft by lock rings |08 received in grooves|09 of the eccentrices so that the cylinders are anchored in xedlongitudinal position relative to the ecy centric-shaft by theanti-friction bearings. The eccentrics are counter-balanced intermediatethe anti-friction bearings .by counter-weights ||0 that are attached tothe shaft diametrically opposite the high portions of the eccentrics asshown in Figs. 1,2, and 3.v

The case may be provided with a lubricant The case may have a drainopening v||3 in the bottom closed by a'p1ug`||4. If desired, the casemay have an inspection opening I I5 to determine level of lubricantinthe case. This opening may be closed by a plugk ||6 as shown in Fig.1.

In assembling the pump, the anti-friction bearings |0| and |02 areinstalled upon the eccentric shaft 2| with the outer races |03 and |04engaging within the bearing .seats |05 and |06 of the leccentrically-supported cylindersy 92 and 93 while the shaft isexterorly of the case. After insertapplied on the journals 20 and 2| ofthe shaft 22. The elastic chambers 50 and 5| are then cemented to themetal liners or sleeves '81 and 9| and the metal liners 9| are sleevedover the eccentric cylinders 92 and 93 and secured by the fasteningdevices 88. The shaft assembly is then placed inthe case so that thebearing I4 enters the housing I2. The four legs of the elastic chamberswill slide freely into the opening 8 of the case and thel grooves 94 inthe eccentric cylinders 92 and 93 are located in registry with the rib46, after which u the fastening devices 88 are inserted through the caseopenings 89 to anchor'the outer metal linersV or sleeves 81. Theremovable end platek 6 is then slid into position on the shaft so thatthe bearing v I1 enters the bearing housing I5 and the plate is securedto the case by means of the studs 24. The

case is then turned upside down and the open ends or collars 84 of thechambers are pulled through the port openings 40-,-4| and 42-43 in thesubbase after which the subbase is at.

tached to the case by the fastening devices 38. The base manifold 53 isthen set in position. on the subbase with the tapering flanges 64thereon entering within the open endslof the elastic chamcant to thelevel opening lbers so as to bell the vwalls thereof outwardly intosealing engagement with the subbase as shown in Figs. 1, 2, and 3. Thestuds I2 are then applied and thenuts 15 thereon drawn tight to assure'a ture illustrated, the elastic members 50 and 5| must be constructedof a material that does not deteriorate in oil, for example, one of thesynthetic plastics now on the market. However, the individual bearingsmay be sealed so that ordinary rubber might be used in formation of theelastic chambers without departing from the spirit of the invention. Thepump is then mounted on a suitable base and connected with a prime movercapable of rotating' the shaft at a desired speed, vfor example, .600 R,P. M. In operation, the eccentric shaft 22 is rotated causing rotationtherewith of the inner races 99 and |00 of the anti-friction bearingsI0! and |02. -The balls of the bearings then planetate in the outerraces |03 and |04 so that the eccentric cylinders remain in their samerelative positions with'ree spect to rotation, however, the axialcenters of the eccentric cylinders will be caused to gyrate about therotational axis of the shaft in an amount equivalent to the throw of theeccentrics. At the maximum throw of the eccentrics, the inner and outerwalls of the Chambers are tightly compressed as in the case of the unitillustra-ted at the left-hand side of Fig. l. Instead of a point or linecontact of the walls, the actual Contact is suicient to effect afluid-tight seal and the area of contact travels progressively aroundthe elastic chambers from the intake to the discharge sides, therebycausing an intake of fluid through the inlet ports, which discharges areprogressively moved ahead of the contact area to be expelled through theoutlet ports when the eccentrics are in downward position as shown. inFig. 2.

The most critical part of the elastic chambers is the closed circularends of the leg portions thereof and these parts may be reinforced byfabric or similar reinforcing material. A short distance from the openends of the elastic chambers there is also a flexing as indicated atpoints ||1 and IIB. The point in Fig. 3 illustrates how the pressurewould. slightly stretch the wall of the chamber out against the rib 46under pressure so that the rib protects the collarportions 84 of thechambers from further expansion. On the suction side the liners areslightly stretched as shown at ||1 (Fig. 3)

When the eccentrics are down closing both ports, the elastic materialforming the chambers is pressed down by the eccentrics and the materialis in unstretched condition (see Fig. 2). As the elastic material wearsfrom abrasives from fluid running through it, the point of contact maybe corrected by applying a shim between the inner sleeves '|1 andeccentric cylinders 92 and 93.

It is thus obvious that the fluid is drawn through the ports 40 and 42into the open'ends of the elastic chambers and isformed progressively bythe contact area of the walls through the elastic chambers to thedischarge ports incidental to rotationof the eccentrics.vliiressing-together of the inner and outer walls of the. chambers makesa pressure-tight and Vcontinuous seal s0 that there is no loss inpressure or back leakage through the intake ports.v It will beparticularly noted that since the inner and outer walls are anchoredrespectively to the case andeccentric cylinders the elastic chamberswill be forcibly opened thereby to effect full intake capacity thereof.

Since the eccentrics of the units are arranged in diametrically oppositedirections relative to each other, one o'f the units will be drawing inof fluid while the other unit is discharging fluid. Thus, constant,uniform pressure is maintained in the discharge manifold of the manifoldbase.

If'the pump isused for operating on an elastic fluid such as air, thecase may be lled with oil and the oil pumped through a radiator (notshown) to absorb the heat of compression or the case may be providedwith a jacket ||9 through which a cooling medium is circulated as shownin Fig. 8. i

Theform of the invention illustrated in Figs. 9 tov15 inclusive includesone or more units. the operating chambers of which have one Side formedof a flexible member. In this form, |20 designates a housing or casingcomposed of a base section `|2| and an upper or cover lsection |22. Thebase section |2| has a semi-cylindrical wall |23 supported inhorizo-ntal position on legs |24 and the ends of the wall are closed byends |25, The wall |23 has openings |26 and |21 (Fig. l0) disposed onopposite sides of'the horizontal center thereof and arranged in pairslongitudinally spaced to connect with intake and discharge manifolds |28and |29 which are illustrated as being formed as integral parts 4of thebase. The manifolds have inlet and outlet connections |30 and |3|located intermediate the pairs of openings as shown in Fig. 10 andindicated indotted lines in Fig. 9, the connections being'suitablymachined for receiving ducts (not shown) by which fluid is admitted intoand discharged from the pump. The rim of the wall |23 and ends |25 areflanged outwardly to form a seating face |32` 4for the cover section|22.` The cover section |22 also includes a semi-cylindricalwall'portion I33'corresponding to the wall portion |23 and ends |34registering with the walls |25 and which have faces |35 adapted to seaton' the faces |32 to form an enclosed cylindrical comregistering edgesthereof at one end of the cas ing with an opening |43 counterbored toaccom modate a sealing ring |44. The inner sides of the end walls areprovided with recesses |45 and v tudinal wedges |83.

stators and into threaded sockets to accommodate counterbalance weights|63 for counterbalancing the eccentrics and the parts carried thereby.The counterbalancing weights are offset to gyrate in the spaces |64circumferentially of the shaft bearings |41 and |48 and have collars |65secured on the shaft in position to give the correct dynamic balance byset screws |66.

Pressed upon each of the races |51 are eccentric pistons |61 eachincluding a substantially sleeve-like body having an inner diameter toaccommodate the outer races |51 of the bearings and provide a stopshoulder |68 at one end cooperating kwith a lock ring |69 at the otherfor maintaining longitudinal position of the eccentric pistons as shownin Fig. 9. The circumferential faces of the eccentric pistons terminateat the ends in tapering end faces and |1|.

Mounted on the eccentric pistons are flexible liners |12 formed ofelastic material; for example, rubber, and molded upon the eccentricpistons to provide the necessary shape therefor. To facilitate anchorageof the liners, the eccentric pistons are preferably provided with aseries of dovetail grooves |13 extending ciroumferentially thereof toreceive portions |14 of the rubber therein so that the intermediateportions 0f the liners are firmly anchored to the pistons; however, theend portions |15 and |16` are free of the tapered `portions |10 and |1|to permit flexing. thereof upon actuation of the piste-ns as laterdescribed.

The liners are provided with flanges |11 and |18 for attachment to thestators |19. The annular portions of the liners terminate at ,pointssubstantially over the ports 26 and |21 in flaps |80 and |8|, the endsof which are received in a substantially V-shaped longitudinal recess|82 of the stators |19 and are clamped therein by longi- The wedges |83are drawn into clamping engagement by screws |84 having shanks extendingthrough openings |85 inthe |86 of the wedges as shown in Fig, 10. Inorder to enhance the seal and more securely anchor the flaps, the flapsare preferably provided with longitudinal ribs |81 engaged in grooves|88 in the sides of the recesses. The flanges |11 and |18 overlieflanges |89 andi 90 of the stators and are secured thereby by clampinglrings |9| by fastening devices |92 extending through openings |93 inthe clamping rings and into threaded sockets |94 of the flanges |89 and|90.

The stators are also of sleeve-like formation and the end flanges |89and |90 cooperate with k an intermediate rib |95 to center the statorWithin .are constructed to press the outer faces of the liners intocontact with the inner faces ofthe stators progressively from the inletport toward the exhaust port to effect movement of fluid therethroughsubstantiallyv in the manner described in the rst form of the invention.The ends of v the stators therefore, have inwardly tapering ends |98 and|99 corresponding to the tapers |10 and |1| of the pistons. A

In order to enhance the seal and gripping engagement of the flanges ofthe liners, the anges v are preferably providedy on the facing sidesthereof with arcuate ribs 200 engaged in corresponding arcuate grooves20| of the stators. A seal is effected around the ports |96 and |91 bygaskets 202 inserted between the stators and the casin |20. f In orderto prevent rotation of the piston members, and thus reduce stress in thenexingposit tions of the liners ends thereof terminate in annularring-shaped extensions 203 of substantially,"l channel-shaped crosssection to accommodate rollers 204 therein, the rollers being retainedon pins 205 having the ends thereof fixed in suitable openingsin theside flanges 206 and 206 of the., extensions, ythe rollers beingpositioned in open.

ings 201 formed in the web portions ofthe ringlike extensions wherebythe major portion of the rollers are adapted to engage in spaces 208kformed between teeth 209 within the inner ldiameter of the clampingrings |9| as shown in Fig. 1. Therefore, when the eccentrics are rotatedthe piston members are prevented from rotating by reason of engagementof the rollers between the teeth of the clampingrings, however, thepistons move eccentrically with rotation of the eccentrics so that therollers progressively enter the 'spaces between the respective teeth andare retracted v therefrom incidental to gyration of the eccentrics. Asshown in Fig. 14, the liners are reinforced to .withstand the'hydrostatic pressurewith one or more layers of circumferential cords 2|0with one or more layers of transverse cords 2| The cords are preferablyof cotton, rayon, nylon, er

steel strands, and are completely surrounded by the rubber or otherflexible plastic from which the liners are formed.

.The form of the pump just described is assembled as follows:

. The liners |12 are molded on the eccentric pistons and are firmlysecured thereto when the rubber composing the liners is vulcanized, amechanical bond being maintained by the annular dovetail grooves andthrough bonding of the rubber to the metal.

The guide rollers 204 are then installed by means of the pins 205 onwhich the rollers turn.l

The eccentric pistons carrying the` liners are inserted within thestators |19 and lthe'flanges of the liners are clamped to the flanges ofthe stators by the clamping rings 9|, the rings being secured by thefastening'devices-I92 so that 'the flanges of the liners are anchoredconcentrically of the stators and in sealed relation therewith. Theflexible end flaps and |8| of the liners rhaving been inserted in therecesses |82, are.

drawn into sealing engagement with the walls of the recesses bytightening the screws |84 to draw the wedges |83 therebetween. Inapplying the liners to the stators, care is taken that the beads or ribsengage in the grooves of the stator. Since the grooves are slightlysmaller than the lbeads or ribs, they provide a tight seal for the fluidspaces or courses of the piston chambers which is that space between theeccentric pistons and the vinner faces of the stators. The'bearing races|52 are then pressed into the pistons and retained 9 by the lock rings|60. The anti-friction bearings |56 are then applied to the eccentricportions of the crank shaft |53 and the'piston assemblies are sleevedthereover, after which the retainer rings |50 are applied to the groovesof the eccentric shaft to retain the assemblies from longitudinalmovement. The gasket rings 202 are then mounted in recesses of thestators and preferably cemented in position to encompassthe intake anddischarge ports |96 and |91. The counterweights |63 are then applied tothe ends of the shaft followed by the anti-friction bearings |41 and |48and the seal ring assembly |44.

The entire shaft assembly is then inserted into the lower section of thepump casing so that the ports in the stators register with the openingsin the casing. The counterweights maythen be adjusted and secured by theset'screws |66 to provide dynamic balance.

The top section of the casing is then set in place withthe gasket |39 inthe grooves of one of the sections. The parts of the casing are thendrawn tightly together by the fastening devices |40 thus clamping theouter races of the shaft bearings |41 and |48 and the stators firmly inposition.

A lubricating oil is then poured into the crankcase up to the level ofthe opening for a plug 2|2. The lubricating oil is preferably of lightweight and serves the dual purpose of lubricating the outside of theliners |12 where they contact and rub slightly the tapered surfaces ofthe eccentric pistons and to lubricate the anti-friction bearings. Afterinsertion of the lubricating oil, the plug is applied in the opening sothat the lubricating oil is retained in the casing with all the workingparts of the pump submerged. The inlet and outlet connections for thepump are then connectecl` with suitable ducts through which fluid to beacted upon by the pump is admitted to the inlet side, and dischargedunder pressure from the outlet side. The projecting end of the shaft isconnected in any suitable manner to a source of power to effect rotationthereof.

The crankshaft of the pump may be rotated in either 'direction and asthe shaft rotates, the eccentric pistons are forced to execute suchmotion that each point thereof traverses in phase a circle of diameterequal to twice the eccentricity crank |53 in a plane perpendicular tothe crankshaft axis. The liners are thus caused to be pressed tightlyagainst the inner surfaces of the stators forming a pressure-tight sealacross the piston chambers or ducts betweenthe inlet and outlet portswhich seal traverses around the chambers in phase with the eccentrics onthe crankshaft to force the iluid being pumped from the inlet ports intothe outlet ports.

The two eccentric pistons operating 180 out of phase causes asubstantially uniform flow of fluid. The loose portions of the linersadjacenlt the tapered portions of the pistons cross the sides of thepiston chambers and flex to and from contact with the inward tapers |98of the stators and points thereon traverse approximately the surface ofa cone, the apex of which is stationary where the liners are secured tothe stators. The end flaps of the liners, that is, the moving portionsthereof, flex inwardly into the spaces between the pistons and thewedges |83 somewhat as described in the first form of the invention.Stresses are partially relieved from these flaps and the circularflexing section of the liner through engagement ofthe rollers 204 withthe teeth on the guides |9|.

To take the pump apart for maintenance purposes, it is only necessary toremove the fastening devices |40 and lift the upper section of thecasing from the lower section. The inlet and outlet piping to the pumpneed not be disturbed. The crankshaft asssembly can then be lifted outof the lower section of the casing and the two pump assemblies removedfrom the ends of the shaft, after which the pump assemblies may berepaired or new assemblies installed as previously described.

From the foregoing it is obvious that I have provided a simple,light-weight pump structure which has a large capacity at relatively lowspeed and which is adapted to operate on fluids which contain abrasivessuch as the drilling fluidl used in drilling of wells. It is alsoobvious that the apparatus illustrated and described may be" adapted toactuate as a motor by supplying an operating fluid under pressure to theinlet thereof so that the fluid will effect actuation of the eccentricshaft.

What I claim and desire to secure by Letters Patent is: f t

1. An apparatus of the character describedincluding, a. casing, a shaft,means rotatably mounting the shaft in the casingI an eccentric on theshaft, a cylinder supported on the eccentric, sleeve-like linersremovably mounted within the casing and upon the circumference of thecylinder, a flexible duct having opposite walls connected with the sleeIe-like liners, said case llaving inlet and outlet onnections with therespective ends 0f shaft t0 effe gyraticn of the axis of the cylinderabout the ax s of the shaft incidental to rotation of the eccentric, toeffect progressive expansion and contraction of the duct about thecylinder.

2. A device lof the character described including, a case, a subbasemounted on the case and having spaced ports, a manifold base havingports registering with the ports in thesubbase,l flanges encircling saidports, a substantially horseshoeshaped duct formed of flexible materialand having a side wall connected with the case, a shaft, means rotatablymounting the shaft concentrically of the case, an eccentric on theshaft, a cylinder carried by said eccentric for supporting the oppositewall of the duct and necks on the end*v of said ducts engaged betweensaid flanges, means connecting the manifold base with the subbase toeffect a leak-tight connection with said nccks,V and means for rotatingthe shaftto effect lgyration of the axis of the cylinder about the axisof the shaft and progressive contraction and expan- 'sion of the ductincidental to rotation of the eccentric.

3. A device of the character described including, a case, a subbasemounted on the case and having spaced ports, a manifold `base havingports registering with the ports in the subbase, flanges encircling saidports, a substantially horseshoe-shaped duct formed of flexible materialand having a side connected with the case, a shaft, means rotatablymounting the shaft concentrically of the case, an eccentric on theshaft, spaced bearings on the eccentric. a cylinder carried by saidbearings for supporting the opposite wall of the duct and necks on theend of said ducts engaged between said flanges, means connecting themanifold base with the subbase to effect a leak-tight connection withsaid necks, and means for rotating the shaft to effect gyration of theaxis of the cylinder about the axis of the shaft and progressivecontraction and expansid du and means for rotating the\f 'I siori'of theduct incidental -to rotation of the eccentric.

4. In anv apparatus of the character described including inner andouterannular members cooperating to provide a space between saidmembers, means including flexing portions closing ends of said'space andhaving connection with the members to provide a. duct between saidmembers, inlet andy outlet connections in said duct,

means supporting said members with one of the membersin eccentricrelation to the other for providing a restriction in said duct, one ofsaid .members being movable relative to the other for advancing saidrestriction from one of said connections toward the other, an annularguide on one of the members having spaced teeth arrangedvcircumferentially about the axis of said member, and means carried bythe other member for engaging in the spaces between said teeth forpreventing relative rotation of said members.

5. In an apparatus of the character described including an annularstator, an annular piston within the stator to provide` a space betweensaid l pist/,on and stator, means including exing portions `closing endsof said space for forming a substantially annular duct, inlet and outletconnections with said duct, means supporting the piston in eccentricrelation to the stator for providing a restriction in said duct, meansfor rtating said supportingfmeans for advancing said restriction fromone of said connections toward the other, and means on the piston havingintermeshing connection with the stator for preventing rotation 'of thepiston within the stator.

6. In an apparatus ofthe character described including an annularstator, a sleeve-like piston in the stator and cooperating therewith toprovide a space therebetween, a flexible liner xed circumferentially ofthe piston and having ilexing portions closing ends of said space andcOnnected with the stator to provide a duct between said members, saidstator having inlet and outlet openings aps on said liner havingconnection with'the stator intermediate said openings, means supportingsaid piston ineccentric relation with @stator wherr the piston assemblyis inserted in said section, a semi-cylindrical cover section `for saidbase section for closing over the top'of the pump assembly, gasket meansbetween said piston assembly and the basesection for sealing about said'ports and registering openings, and fastening 'devices' for drawing thesections together aboutv the piston assembly.

Number Name Date 1,765,360' Baumann June 24, 1930 2,246,487 `Fraser June17,1941 2,251,235 Weydell July 29, '1941 2,403,572 Wittenberg July 9,1946 FOREIGN PATENTS Number p Country Date 8. In a device of thecharacter decribed, a shaft having an eccentric portion and spacedbearing portions at the ends thereof, anti-friction bearings on thebearing portions of said shaft, a sleeve-like piston on the eccentricportion, an annular stator encircling the piston and having an innerdiameter to provide a space therebetween, said stator having spacedports connected with said space, a flexible liner attached to the pistonand having flexible side portions attached to the stator, flaps on endsof the liner and anchored to the lstator intermediate said ports, ahousing including a base section having openings registering with theports of the stator, gasket means encompassing the ports and saidOpenings to effect a seal between the stators and saidJOase section, acover section for said housing extending over the top of the stator,said cover and base section having recesses for receiving the bearings,

and fastening devices for drawing the sections together to clamp thestator from movement in said housing.

9. An apparatus of the character described including, an outer annularmember, an inner annular member cooperating with the outer annularmember to provide a space therebetween, resilient means fixedcircumferentially to one of the members and having flexing flangesclosing the sides of said space and xed to the other member to provide aduct between said members lfor passage of fluid, uid inlet and outletconnections on the outer annular member for said duct, ap means on theresilient means and anchored to said other member for forming a divisionbetween the inlet and outlet connections, means supporting the outer ofsaid members in xed position, an eccenltric supporting the inner annularmember with NORVEL DOUGLAS.

REFERENCES CITED The following references are of record in the le ofthis patent:

UNITED STATES PATENTS Great Britain 1938`

